Persil liquid non-bio is great for all-round cleaning, and gentle on sensitive skin. What is the difference between bio and non-bio detergent, and which is right for you? Biological detergents contain stain-busting enzymes, effective in breaking down the protein, starches and fats often found in stains. These enzymes even work at low temperatures. Non-biological detergents don’t contain these enzymes to be a little kinder to skin.